Please use this thread going forward: Romantic Relationships decay/become negative fast with no interaction | EA Forums - 4947168
So I dont know if its related or might be a clue why this is happening, but I noticed a couple of times already sims who are in a romantic relationship will react very negatively if they see your sim just casually talking and using friendly interactions on their spouse/partner... even though the sim dont have the jaelous trait or even if any romantic interactions were used... this is weird and might explain why they loose their romance bar so easily if simple friendly interaction affect their couple, even if those interaction are directed to some other family members... I saw that many times and its suspicious.
It's not quite making sense when my married Sims have a relationship thats above halfway pink and they both start talking about divorce. Especially as their friendship is maxed. They immediately become sad too and their relationship interactions become more difficult. Friendship should count more because how many couples do nothing but romantic interactions for hours and hours and that's exactly what I have to do to keep my Sims in happy relationships.
I edited their preferences in CAS to include each others hair colour, way of life and clothing colour, etc and took away anything that didn't match each other. That helped with their attraction levels but family gameplay is difficult enough unfortunately without couples having to constantly maintain the romance every day. If they don't it drops after a couple of days again and they talk about divorce again. It's quite unpleasant. Sentiments don't count at all either, this couple has really loving sentiments and are best friends too.
Also when they are both satisfied in the relationship it's supposed to build automatically but it definitely isn't. It's dropping instead.
I have Lovestruck and just wanted to add that this has started with one of my couples too. They're romantic partners but don't live together, they are attracted/very attracted to each other and I can easily get them into the Very Satisfied with romance level without much work! However, despite being Very satisfied (which says their relationship should decay slowly over time), over the course of not seeing each other for 24 sim hours their romance bar went from completely pink to a tiny bit of red.
I have never seen a romantic relationship degrade so fast apart from breaking up or divorcing and this couple are still partners. I agree with above posters that some tuning went wrong in one of the last couple of patches because this shouldn't be happening.
